function popup(url){
	var left = (screen.width - 1024)/2;
	var top = (screen.height - 768)/2;

	params  = 'width=1008';//+screen.width;
	params += ', height= 672';//+screen.height;
	params += ', top='+top+', left='+left;
	params += ', top=0, left=0'
	params += ', fullscreen=no';
	params += ', scrollbars=yes';
	newwindow=window.open(url, 'virtualdemo', params);
	
	if (window.focus) {
		newwindow.focus();
	}
	
	return false;
}